Flat panel displays and integrated circuit (IC) structures use silicon-nitrogen (Si-N) based thin films for, among other uses, diffuision masks, oxidation barriers and dielectric layers. Current manufacturing technologies for producing these films use the reaction of silicon sources of the type silane (SiH.sub.4) or dichlorosilane (Cl.sub.2 SiH.sub.2) with ammonia (NH.sub.3) under thermal or plasma assisted conditions inorganic low-pressure chemical vapor deposition (LPCVD), sub-atmospheric pressure CVD (SACVD), or atmospheric pressure CVD (APCVD). Unfortunately, the thermal required temperatures in excess of 1000.degree. C., while plasma assistance still necessitates temperatures in excess of 750.degree. C.
The use of these inorganic thermal and plasma CVD technologies precludes efficient and safe production of Si-N systems due to the implicit restrictions in thermal budget, with processing temperatures exceeding 750.degree. C., and chemical stability, in view of the safety issues pertaining to the application of silane and similar chemistries. Their use requires stringent safety precautions as they can be pyrophoric, toxic, corrosive, or present other hazards. Plasma use, on the other hand, leads to the incorporation, in many cases, of excessive concentrations of hydrogen species, thus limiting the quality of the resulting Si-N thin films. Also, particulate generation in the CVD reactor, resulting from the reaction of silane-type chemistries with ammonia, poses significant tool reliability problems. Therefore, there is a need in the art for an alternative to use of silane and chlorosilanes as raw materials, and a need in the art for a CVD process which does not require plasma.
Alternatives to inorganic CVD techniques have been proposed, but either require difficult to access intermediates, use a high energy environment and/or result in a film in which the electrical properties are compromised. Examples of such alternative systems include that described in U.S. Pat. No. 4,200,666 using trisilylamine ((SiH).sub.3 N) and an inert gas with optional ammonia; the system of diethylsilane and ammonia in an LPCVD system at 800.degree. C. as described In A. Hochberg et al., Mat. Res, Soc. Symp, 24, 509 (1991); and the system of cyclicsilazanes and ammonia in a chemical vapor deposition (CVD) process as described in B. Arkles, "Silicon Nitride From Organosilazane Cyclic And Linear Prepolymers," J. Electrochemical Soc., Vol. 133, No. 1, pp. 233-234 (1986
There is a need in the art for a method of producing silicon-nitrogen based thin films, such as (Sin.sub.x), where x is greater than zero but less than 2, which can operate below the high temperatures necessary for plasma techniques such that use of plasma is optional, which uses a system pressure preferably near atmospheric pressure (without plasma), which is efficient in throughput, and which eliminates the hazards associated with the use of silane and chlorosilanes as raw materials.